There is a very active owners association. See CLICKY
Assuming it is a swing keel if you are thinking of trailoring it then the keel pivot is the main issue. This can not be checked easily.
Other than that just the normal things like rig and sail condition.
I have fond memories of the Catalina 22 or Jaguar 22 as it was known as in the UK. I sailed mine all around the West coast of Scotland and trailored it down to the Adriatic for a summer there.